William Caldwell (towards 1750 – February 20th 1822) was immigrant a Irish in North America which fought at the time of various conflicts like British soldier.

In 1774, it is useful at the time of the Guerre of Dunmore. At the time of the War of independence of the United States of America, Caldwell is used under the orders as Lord Dunmore, at the time of the attack of Norfolk where it will be wounded. It is then named captain of the Rangers de Butler. Based to Strait, it leads a force of 50 rangers in many battles and forwardings to the Kentucky and in Ohio Country. In 1782, it leads its rangers and of the Indians to the victory against the Expédition Crawford then at the time of the Bataille of Blue Licks.

After the war, it settles in the area of Strait and becomes commercial, its associate is Matthew Elliott with which it fought at the time of his military career. When occurs the Guerre of 1812, it receives the command of a unit which one will name the Rangers de Caldwell (or Rangers of the West). It takes part, amongst other things, with the battles of Thames and Longwoods.